反作用控制系统推力器失效的外部检测与诊断

FAILURE DETECTION AND DIAGNOSIS FOR THRUSTERS′ FAILURE IN REACTION CONTROL SYSTEM USING EXTERNAL INFORMATION

关键词:  反作用控制系统  推力器  故障检测  故障诊断

Key words:  Reaction control system  Thruster  Fault detection  Fault diagnosis

摘要:

通过推进系统外部可测的姿态信息，利用强跟踪滤波器和多模预报估计器，研究了一类非线性系统常值阶跃型故障和间歇性故障的检测与分离问题。对关机失效，利用强跟踪滤波器获得故障效应的估计，检测逻辑采用改进的贝叶斯分类方法，依据推力器失效效应的方向性进行故障单元的分离；对开机失效，采用多模预报，根据相应残差向量范数的比较进行故障的即时无阈值判别，同时完成了故障后系统状态的重构问题。以一类大型航天器的反作用姿态控制系统为例，对其中出现的推力器失效进行了故障识别仿真研究，表明所提方法是有效的。

Abstract:

According to external measurable attitude information,a novel failure detection and diagnosis(FDD) scheme for nonlinear system was developed for the identification of thrusters′ open failure and close failure in Reaction Control System(RCS)by means of Strong Tracking Filter(STF) and Multi Model Predictor(MMP).In the close failure case,fault amplitued can be directly acquired using the modified STF in real time.According to the estimated failure,a Modified Bayes′ Decision Law was proposed to lessen alarm delay.In addition,based on the fault direction,the failed thruster was isolated.In the open failure case a novel MMP approach which can attract failure information from occasionally appearing effect and at the same time achieve the reconfiguration of the estimated state under the failure was presented.Finally the proposed approach was used in RCS of a spacecraft and the efficacy of the FDD scheme was shown